2 * Network proxy abstraction in PuTTY
4 * A proxy layer, if necessary, wedges itself between the network
5 * code and the higher level backend.
12 #define DEFINE_PLUG_METHOD_MACROS
17 #define do_proxy_dns(conf) \
18 (conf_get_int(conf, CONF_proxy_dns) == FORCE_ON || \
19 (conf_get_int(conf, CONF_proxy_dns) == AUTO && \
20 conf_get_int(conf, CONF_proxy_type) != PROXY_SOCKS4))
23 * Call this when proxy negotiation is complete, so that this
24 * socket can begin working normally.
26 void proxy_activate (Proxy_Socket p
)
30 long output_before
, output_after
;
32 p
->state
= PROXY_STATE_ACTIVE
;
34 /* we want to ignore new receive events until we have sent
35 * all of our buffered receive data.
37 sk_set_frozen(p
->sub_socket
, 1);
39 /* how many bytes of output have we buffered? */
40 output_before
= bufchain_size(&p
->pending_oob_output_data
) +
41 bufchain_size(&p
->pending_output_data
);
42 /* and keep track of how many bytes do not get sent. */
45 /* send buffered OOB writes */
46 while (bufchain_size(&p
->pending_oob_output_data
) > 0) {
47 bufchain_prefix(&p
->pending_oob_output_data
, &data
, &len
);
48 output_after
+= sk_write_oob(p
->sub_socket
, data
, len
);
49 bufchain_consume(&p
->pending_oob_output_data
, len
);
52 /* send buffered normal writes */
53 while (bufchain_size(&p
->pending_output_data
) > 0) {
54 bufchain_prefix(&p
->pending_output_data
, &data
, &len
);
55 output_after
+= sk_write(p
->sub_socket
, data
, len
);
56 bufchain_consume(&p
->pending_output_data
, len
);
59 /* if we managed to send any data, let the higher levels know. */
60 if (output_after
< output_before
)
61 plug_sent(p
->plug
, output_after
);
63 /* if we were asked to flush the output during
64 * the proxy negotiation process, do so now.
66 if (p
->pending_flush
) sk_flush(p
->sub_socket
);
68 /* if we have a pending EOF to send, send it */
69 if (p
->pending_eof
) sk_write_eof(p
->sub_socket
);
71 /* if the backend wanted the socket unfrozen, try to unfreeze.
72 * our set_frozen handler will flush buffered receive data before
73 * unfreezing the actual underlying socket.
76 sk_set_frozen((Socket
)p
, 0);
79 /* basic proxy socket functions */
81 static Plug
sk_proxy_plug (Socket s
, Plug p
)
83 Proxy_Socket ps
= (Proxy_Socket
) s
;
90 static void sk_proxy_close (Socket s
)
92 Proxy_Socket ps
= (Proxy_Socket
) s
;
94 sk_close(ps
->sub_socket
);
95 sk_addr_free(ps
->remote_addr
);
99 static int sk_proxy_write (Socket s
, const char *data
, int len
)
101 Proxy_Socket ps
= (Proxy_Socket
) s
;
103 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
104 bufchain_add(&ps
->pending_output_data
, data
, len
);
105 return bufchain_size(&ps
->pending_output_data
);
107 return sk_write(ps
->sub_socket
, data
, len
);
110 static int sk_proxy_write_oob (Socket s
, const char *data
, int len
)
112 Proxy_Socket ps
= (Proxy_Socket
) s
;
114 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
115 bufchain_clear(&ps
->pending_output_data
);
116 bufchain_clear(&ps
->pending_oob_output_data
);
117 bufchain_add(&ps
->pending_oob_output_data
, data
, len
);
120 return sk_write_oob(ps
->sub_socket
, data
, len
);
123 static void sk_proxy_write_eof (Socket s
)
125 Proxy_Socket ps
= (Proxy_Socket
) s
;
127 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
131 sk_write_eof(ps
->sub_socket
);
134 static void sk_proxy_flush (Socket s
)
136 Proxy_Socket ps
= (Proxy_Socket
) s
;
138 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
139 ps
->pending_flush
= 1;
142 sk_flush(ps
->sub_socket
);
145 static void sk_proxy_set_private_ptr (Socket s
, void *ptr
)
147 Proxy_Socket ps
= (Proxy_Socket
) s
;
148 sk_set_private_ptr(ps
->sub_socket
, ptr
);
151 static void * sk_proxy_get_private_ptr (Socket s
)
153 Proxy_Socket ps
= (Proxy_Socket
) s
;
154 return sk_get_private_ptr(ps
->sub_socket
);
157 static void sk_proxy_set_frozen (Socket s
, int is_frozen
)
159 Proxy_Socket ps
= (Proxy_Socket
) s
;
161 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
162 ps
->freeze
= is_frozen
;
166 /* handle any remaining buffered recv data first */
167 if (bufchain_size(&ps
->pending_input_data
) > 0) {
168 ps
->freeze
= is_frozen
;
170 /* loop while we still have buffered data, and while we are
171 * unfrozen. the plug_receive call in the loop could result
172 * in a call back into this function refreezing the socket,
173 * so we have to check each time.
175 while (!ps
->freeze
&& bufchain_size(&ps
->pending_input_data
) > 0) {
179 bufchain_prefix(&ps
->pending_input_data
, &data
, &len
);
180 if (len
> lenof(databuf
))
181 len
= lenof(databuf
);
182 memcpy(databuf
, data
, len
);
183 bufchain_consume(&ps
->pending_input_data
, len
);
184 plug_receive(ps
->plug
, 0, databuf
, len
);
187 /* if we're still frozen, we'll have to wait for another
188 * call from the backend to finish unbuffering the data.
190 if (ps
->freeze
) return;
193 sk_set_frozen(ps
->sub_socket
, is_frozen
);
196 static const char * sk_proxy_socket_error (Socket s
)
198 Proxy_Socket ps
= (Proxy_Socket
) s
;
199 if (ps
->error
!= NULL
|| ps
->sub_socket
== NULL
) {
202 return sk_socket_error(ps
->sub_socket
);
205 /* basic proxy plug functions */
207 static void plug_proxy_log(Plug plug
, int type
, SockAddr addr
, int port
,
208 const char *error_msg
, int error_code
)
210 Proxy_Plug pp
= (Proxy_Plug
) plug
;
211 Proxy_Socket ps
= pp
->proxy_socket
;
213 plug_log(ps
->plug
, type
, addr
, port
, error_msg
, error_code
);
216 static int plug_proxy_closing (Plug p
, const char *error_msg
,
217 int error_code
, int calling_back
)
219 Proxy_Plug pp
= (Proxy_Plug
) p
;
220 Proxy_Socket ps
= pp
->proxy_socket
;
222 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
223 ps
->closing_error_msg
= error_msg
;
224 ps
->closing_error_code
= error_code
;
225 ps
->closing_calling_back
= calling_back
;
226 return ps
->negotiate(ps
, PROXY_CHANGE_CLOSING
);
228 return plug_closing(ps
->plug
, error_msg
,
229 error_code
, calling_back
);
232 static int plug_proxy_receive (Plug p
, int urgent
, char *data
, int len
)
234 Proxy_Plug pp
= (Proxy_Plug
) p
;
235 Proxy_Socket ps
= pp
->proxy_socket
;
237 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
238 /* we will lose the urgentness of this data, but since most,
239 * if not all, of this data will be consumed by the negotiation
240 * process, hopefully it won't affect the protocol above us
242 bufchain_add(&ps
->pending_input_data
, data
, len
);
243 ps
->receive_urgent
= urgent
;
244 ps
->receive_data
= data
;
245 ps
->receive_len
= len
;
246 return ps
->negotiate(ps
, PROXY_CHANGE_RECEIVE
);
248 return plug_receive(ps
->plug
, urgent
, data
, len
);
251 static void plug_proxy_sent (Plug p
, int bufsize
)
253 Proxy_Plug pp
= (Proxy_Plug
) p
;
254 Proxy_Socket ps
= pp
->proxy_socket
;
256 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
257 ps
->sent_bufsize
= bufsize
;
258 ps
->negotiate(ps
, PROXY_CHANGE_SENT
);
261 plug_sent(ps
->plug
, bufsize
);
264 static int plug_proxy_accepting (Plug p
, OSSocket sock
)
266 Proxy_Plug pp
= (Proxy_Plug
) p
;
267 Proxy_Socket ps
= pp
->proxy_socket
;
269 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
270 ps
->accepting_sock
= sock
;
271 return ps
->negotiate(ps
, PROXY_CHANGE_ACCEPTING
);
273 return plug_accepting(ps
->plug
, sock
);
277 * This function can accept a NULL pointer as `addr', in which case
278 * it will only check the host name.
280 static int proxy_for_destination (SockAddr addr
, char *hostname
, int port
,
285 int hostip_len
, hostname_len
;
286 const char *exclude_list
;
289 * Special local connections such as Unix-domain sockets
290 * unconditionally cannot be proxied, even in proxy-localhost
291 * mode. There just isn't any way to ask any known proxy type for
294 if (addr
&& sk_address_is_special_local(addr
))
295 return 0; /* do not proxy */
298 * Check the host name and IP against the hard-coded
299 * representations of `localhost'.
301 if (!conf_get_int(conf
, CONF_even_proxy_localhost
) &&
302 (sk_hostname_is_local(hostname
) ||
303 (addr
&& sk_address_is_local(addr
))))
304 return 0; /* do not proxy */
306 /* we want a string representation of the IP address for comparisons */
308 sk_getaddr(addr
, hostip
, 64);
309 hostip_len
= strlen(hostip
);
311 hostip_len
= 0; /* placate gcc; shouldn't be required */
313 hostname_len
= strlen(hostname
);
315 exclude_list
= conf_get_str(conf
, CONF_proxy_exclude_list
);
317 /* now parse the exclude list, and see if either our IP
318 * or hostname matches anything in it.
321 while (exclude_list
[s
]) {
322 while (exclude_list
[s
] &&
323 (isspace((unsigned char)exclude_list
[s
]) ||
324 exclude_list
[s
] == ',')) s
++;
326 if (!exclude_list
[s
]) break;
330 while (exclude_list
[e
] &&
331 (isalnum((unsigned char)exclude_list
[e
]) ||
332 exclude_list
[e
] == '-' ||
333 exclude_list
[e
] == '.' ||
334 exclude_list
[e
] == '*')) e
++;
336 if (exclude_list
[s
] == '*') {
337 /* wildcard at beginning of entry */
339 if ((addr
&& strnicmp(hostip
+ hostip_len
- (e
- s
- 1),
340 exclude_list
+ s
+ 1, e
- s
- 1) == 0) ||
341 strnicmp(hostname
+ hostname_len
- (e
- s
- 1),
342 exclude_list
+ s
+ 1, e
- s
- 1) == 0)
343 return 0; /* IP/hostname range excluded. do not use proxy. */
345 } else if (exclude_list
[e
-1] == '*') {
346 /* wildcard at end of entry */
348 if ((addr
&& strnicmp(hostip
, exclude_list
+ s
, e
- s
- 1) == 0) ||
349 strnicmp(hostname
, exclude_list
+ s
, e
- s
- 1) == 0)
350 return 0; /* IP/hostname range excluded. do not use proxy. */
353 /* no wildcard at either end, so let's try an absolute
354 * match (ie. a specific IP)
357 if (addr
&& strnicmp(hostip
, exclude_list
+ s
, e
- s
) == 0)
358 return 0; /* IP/hostname excluded. do not use proxy. */
359 if (strnicmp(hostname
, exclude_list
+ s
, e
- s
) == 0)
360 return 0; /* IP/hostname excluded. do not use proxy. */
365 /* Make sure we really have reached the next comma or end-of-string */
366 while (exclude_list
[s
] &&
367 !isspace((unsigned char)exclude_list
[s
]) &&
368 exclude_list
[s
] != ',') s
++;
371 /* no matches in the exclude list, so use the proxy */
375 SockAddr
name_lookup(char *host
, int port
, char **canonicalname
,
376 Conf
*conf
, int addressfamily
)
378 if (conf_get_int(conf
, CONF_proxy_type
) != PROXY_NONE
&&
379 do_proxy_dns(conf
) &&
380 proxy_for_destination(NULL
, host
, port
, conf
)) {
381 *canonicalname
= dupstr(host
);
382 return sk_nonamelookup(host
);
385 return sk_namelookup(host
, canonicalname
, addressfamily
);
388 Socket
new_connection(SockAddr addr
, char *hostname
,
389 int port
, int privport
,
390 int oobinline
, int nodelay
, int keepalive
,
391 Plug plug
, Conf
*conf
)
393 static const struct socket_function_table socket_fn_table
= {
400 sk_proxy_set_private_ptr
,
401 sk_proxy_get_private_ptr
,
403 sk_proxy_socket_error
406 static const struct plug_function_table plug_fn_table
= {
414 if (conf_get_int(conf
, CONF_proxy_type
) != PROXY_NONE
&&
415 proxy_for_destination(addr
, hostname
, port
, conf
))
420 char *proxy_canonical_name
;
424 if ((sret
= platform_new_connection(addr
, hostname
, port
, privport
,
425 oobinline
, nodelay
, keepalive
,
430 ret
= snew(struct Socket_proxy_tag
);
431 ret
->fn
= &socket_fn_table
;
432 ret
->conf
= conf_copy(conf
);
434 ret
->remote_addr
= addr
; /* will need to be freed on close */
435 ret
->remote_port
= port
;
438 ret
->pending_flush
= 0;
439 ret
->pending_eof
= 0;
442 bufchain_init(&ret
->pending_input_data
);
443 bufchain_init(&ret
->pending_output_data
);
444 bufchain_init(&ret
->pending_oob_output_data
);
446 ret
->sub_socket
= NULL
;
447 ret
->state
= PROXY_STATE_NEW
;
448 ret
->negotiate
= NULL
;
450 type
= conf_get_int(conf
, CONF_proxy_type
);
451 if (type
== PROXY_HTTP
) {
452 ret
->negotiate
= proxy_http_negotiate
;
453 } else if (type
== PROXY_SOCKS4
) {
454 ret
->negotiate
= proxy_socks4_negotiate
;
455 } else if (type
== PROXY_SOCKS5
) {
456 ret
->negotiate
= proxy_socks5_negotiate
;
457 } else if (type
== PROXY_TELNET
) {
458 ret
->negotiate
= proxy_telnet_negotiate
;
460 ret
->error
= "Proxy error: Unknown proxy method";
464 /* create the proxy plug to map calls from the actual
465 * socket into our proxy socket layer */
466 pplug
= snew(struct Plug_proxy_tag
);
467 pplug
->fn
= &plug_fn_table
;
468 pplug
->proxy_socket
= ret
;
471 proxy_addr
= sk_namelookup(conf_get_str(conf
, CONF_proxy_host
),
472 &proxy_canonical_name
,
473 conf_get_int(conf
, CONF_addressfamily
));
474 if (sk_addr_error(proxy_addr
) != NULL
) {
475 ret
->error
= "Proxy error: Unable to resolve proxy host name";
479 sfree(proxy_canonical_name
);
481 /* create the actual socket we will be using,
482 * connected to our proxy server and port.
484 ret
->sub_socket
= sk_new(proxy_addr
,
485 conf_get_int(conf
, CONF_proxy_port
),
487 nodelay
, keepalive
, (Plug
) pplug
);
488 if (sk_socket_error(ret
->sub_socket
) != NULL
)
491 /* start the proxy negotiation process... */
492 sk_set_frozen(ret
->sub_socket
, 0);
493 ret
->negotiate(ret
, PROXY_CHANGE_NEW
);
498 /* no proxy, so just return the direct socket */
499 return sk_new(addr
, port
, privport
, oobinline
, nodelay
, keepalive
, plug
);
502 Socket
new_listener(char *srcaddr
, int port
, Plug plug
, int local_host_only
,
503 Conf
*conf
, int addressfamily
)
505 /* TODO: SOCKS (and potentially others) support inbound
506 * TODO: connections via the proxy. support them.
509 return sk_newlistener(srcaddr
, port
, plug
, local_host_only
, addressfamily
);
512 /* ----------------------------------------------------------------------
513 * HTTP CONNECT proxy type.
516 static int get_line_end (char * data
, int len
)
522 if (data
[off
] == '\n') {
523 /* we have a newline */
526 /* is that the only thing on this line? */
527 if (off
<= 2) return off
;
529 /* if not, then there is the possibility that this header
530 * continues onto the next line, if it starts with a space
535 data
[off
+1] != ' ' &&
536 data
[off
+1] != '\t') return off
;
538 /* the line does continue, so we have to keep going
539 * until we see an the header's "real" end of line.
550 int proxy_http_negotiate (Proxy_Socket p
, int change
)
552 if (p
->state
== PROXY_STATE_NEW
) {
553 /* we are just beginning the proxy negotiate process,
554 * so we'll send off the initial bits of the request.
555 * for this proxy method, it's just a simple HTTP
558 char *buf
, dest
[512];
559 char *username
, *password
;
561 sk_getaddr(p
->remote_addr
, dest
, lenof(dest
));
563 buf
= dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
564 dest
, p
->remote_port
, dest
, p
->remote_port
);
565 sk_write(p
->sub_socket
, buf
, strlen(buf
));
568 username
= conf_get_str(p
->conf
, CONF_proxy_username
);
569 password
= conf_get_str(p
->conf
, CONF_proxy_password
);
570 if (username
[0] || password
[0]) {
573 buf
= dupprintf("%s:%s", username
, password
);
575 buf2
= snewn(len
* 4 / 3 + 100, char);
576 sprintf(buf2
, "Proxy-Authorization: Basic ");
577 for (i
= 0, j
= strlen(buf2
); i
< len
; i
+= 3, j
+= 4)
578 base64_encode_atom((unsigned char *)(buf
+i
),
579 (len
-i
> 3 ?
3 : len
-i
), buf2
+j
);
580 strcpy(buf2
+j
, "\r\n");
581 sk_write(p
->sub_socket
, buf2
, strlen(buf2
));
586 sk_write(p
->sub_socket
, "\r\n", 2);
592 if (change
== PROXY_CHANGE_CLOSING
) {
593 /* if our proxy negotiation process involves closing and opening
594 * new sockets, then we would want to intercept this closing
595 * callback when we were expecting it. if we aren't anticipating
596 * a socket close, then some error must have occurred. we'll
597 * just pass those errors up to the backend.
599 return plug_closing(p
->plug
, p
->closing_error_msg
,
600 p
->closing_error_code
,
601 p
->closing_calling_back
);
604 if (change
== PROXY_CHANGE_SENT
) {
605 /* some (or all) of what we wrote to the proxy was sent.
606 * we don't do anything new, however, until we receive the
607 * proxy's response. we might want to set a timer so we can
608 * timeout the proxy negotiation after a while...
613 if (change
== PROXY_CHANGE_ACCEPTING
) {
614 /* we should _never_ see this, as we are using our socket to
615 * connect to a proxy, not accepting inbound connections.
616 * what should we do? close the socket with an appropriate
619 return plug_accepting(p
->plug
, p
->accepting_sock
);
622 if (change
== PROXY_CHANGE_RECEIVE
) {
623 /* we have received data from the underlying socket, which
624 * we'll need to parse, process, and respond to appropriately.
633 int min_ver
, maj_ver
, status
;
635 /* get the status line */
636 len
= bufchain_size(&p
->pending_input_data
);
637 assert(len
> 0); /* or we wouldn't be here */
638 data
= snewn(len
+1, char);
639 bufchain_fetch(&p
->pending_input_data
, data
, len
);
641 * We must NUL-terminate this data, because Windows
642 * sscanf appears to require a NUL at the end of the
643 * string because it strlens it _first_. Sigh.
647 eol
= get_line_end(data
, len
);
654 /* We can't rely on whether the %n incremented the sscanf return */
655 if (sscanf((char *)data
, "HTTP/%i.%i %n",
656 &maj_ver
, &min_ver
, &status
) < 2 || status
== -1) {
657 plug_closing(p
->plug
, "Proxy error: HTTP response was absent",
658 PROXY_ERROR_GENERAL
, 0);
663 /* remove the status line from the input buffer. */
664 bufchain_consume(&p
->pending_input_data
, eol
);
665 if (data
[status
] != '2') {
669 while (eol
> status
&&
670 (data
[eol
-1] == '\r' || data
[eol
-1] == '\n'))
672 buf
= dupprintf("Proxy error: %s", data
+status
);
673 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
686 /* get headers. we're done when we get a
687 * header of length 2, (ie. just "\r\n")
690 len
= bufchain_size(&p
->pending_input_data
);
691 assert(len
> 0); /* or we wouldn't be here */
692 data
= snewn(len
, char);
694 bufchain_fetch(&p
->pending_input_data
, data
, len
);
696 eol
= get_line_end(datap
, len
);
703 bufchain_consume(&p
->pending_input_data
, eol
);
706 eol
= get_line_end(datap
, len
);
711 bufchain_consume(&p
->pending_input_data
, 2);
713 /* proxy activate will have dealt with
714 * whatever is left of the buffer */
724 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
725 PROXY_ERROR_UNEXPECTED
, 0);
729 /* ----------------------------------------------------------------------
733 /* SOCKS version 4 */
734 int proxy_socks4_negotiate (Proxy_Socket p
, int change
)
736 if (p
->state
== PROXY_CHANGE_NEW
) {
739 * version number (1 byte) = 4
740 * command code (1 byte)
743 * dest. port (2 bytes) [network order]
744 * dest. address (4 bytes)
745 * user ID (variable length, null terminated string)
748 int length
, type
, namelen
;
749 char *command
, addr
[4], hostname
[512];
752 type
= sk_addrtype(p
->remote_addr
);
753 if (type
== ADDRTYPE_IPV6
) {
754 p
->error
= "Proxy error: SOCKS version 4 does not support IPv6";
756 } else if (type
== ADDRTYPE_IPV4
) {
758 sk_addrcopy(p
->remote_addr
, addr
);
759 } else { /* type == ADDRTYPE_NAME */
760 assert(type
== ADDRTYPE_NAME
);
761 sk_getaddr(p
->remote_addr
, hostname
, lenof(hostname
));
762 namelen
= strlen(hostname
) + 1; /* include the NUL */
763 addr
[0] = addr
[1] = addr
[2] = 0;
767 username
= conf_get_str(p
->conf
, CONF_proxy_username
);
768 length
= strlen(username
) + namelen
+ 9;
769 command
= snewn(length
, char);
770 strcpy(command
+ 8, username
);
772 command
[0] = 4; /* version 4 */
773 command
[1] = 1; /* CONNECT command */
776 command
[2] = (char) (p
->remote_port
>> 8) & 0xff;
777 command
[3] = (char) p
->remote_port
& 0xff;
780 memcpy(command
+ 4, addr
, 4);
783 memcpy(command
+ 8 + strlen(username
) + 1,
786 sk_write(p
->sub_socket
, command
, length
);
794 if (change
== PROXY_CHANGE_CLOSING
) {
795 /* if our proxy negotiation process involves closing and opening
796 * new sockets, then we would want to intercept this closing
797 * callback when we were expecting it. if we aren't anticipating
798 * a socket close, then some error must have occurred. we'll
799 * just pass those errors up to the backend.
801 return plug_closing(p
->plug
, p
->closing_error_msg
,
802 p
->closing_error_code
,
803 p
->closing_calling_back
);
806 if (change
== PROXY_CHANGE_SENT
) {
807 /* some (or all) of what we wrote to the proxy was sent.
808 * we don't do anything new, however, until we receive the
809 * proxy's response. we might want to set a timer so we can
810 * timeout the proxy negotiation after a while...
815 if (change
== PROXY_CHANGE_ACCEPTING
) {
816 /* we should _never_ see this, as we are using our socket to
817 * connect to a proxy, not accepting inbound connections.
818 * what should we do? close the socket with an appropriate
821 return plug_accepting(p
->plug
, p
->accepting_sock
);
824 if (change
== PROXY_CHANGE_RECEIVE
) {
825 /* we have received data from the underlying socket, which
826 * we'll need to parse, process, and respond to appropriately.
831 * version number (1 byte) = 4
832 * reply code (1 byte)
833 * 90 = request granted
834 * 91 = request rejected or failed
835 * 92 = request rejected due to lack of IDENTD on client
836 * 93 = request rejected due to difference in user ID
837 * (what we sent vs. what IDENTD said)
838 * dest. port (2 bytes)
839 * dest. address (4 bytes)
844 if (bufchain_size(&p
->pending_input_data
) < 8)
845 return 1; /* not got anything yet */
847 /* get the response */
848 bufchain_fetch(&p
->pending_input_data
, data
, 8);
851 plug_closing(p
->plug
, "Proxy error: SOCKS proxy responded with "
852 "unexpected reply code version",
853 PROXY_ERROR_GENERAL
, 0);
861 plug_closing(p
->plug
, "Proxy error: SOCKS server wanted IDENTD on client",
862 PROXY_ERROR_GENERAL
, 0);
865 plug_closing(p
->plug
, "Proxy error: Username and IDENTD on client don't agree",
866 PROXY_ERROR_GENERAL
, 0);
870 plug_closing(p
->plug
, "Proxy error: Error while communicating with proxy",
871 PROXY_ERROR_GENERAL
, 0);
877 bufchain_consume(&p
->pending_input_data
, 8);
881 /* proxy activate will have dealt with
882 * whatever is left of the buffer */
887 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
888 PROXY_ERROR_UNEXPECTED
, 0);
892 /* SOCKS version 5 */
893 int proxy_socks5_negotiate (Proxy_Socket p
, int change
)
895 if (p
->state
== PROXY_CHANGE_NEW
) {
898 * version number (1 byte) = 5
899 * number of available authentication methods (1 byte)
900 * available authentication methods (1 byte * previous value)
901 * authentication methods:
902 * 0x00 = no authentication
904 * 0x02 = username/password
909 char *username
, *password
;
912 command
[0] = 5; /* version 5 */
913 username
= conf_get_str(p
->conf
, CONF_proxy_username
);
914 password
= conf_get_str(p
->conf
, CONF_proxy_password
);
915 if (username
[0] || password
[0]) {
916 command
[2] = 0x00; /* no authentication */
918 proxy_socks5_offerencryptedauth (command
, &len
);
919 command
[len
++] = 0x02; /* username/password */
920 command
[1] = len
- 2; /* Number of methods supported */
922 command
[1] = 1; /* one methods supported: */
923 command
[2] = 0x00; /* no authentication */
927 sk_write(p
->sub_socket
, command
, len
);
933 if (change
== PROXY_CHANGE_CLOSING
) {
934 /* if our proxy negotiation process involves closing and opening
935 * new sockets, then we would want to intercept this closing
936 * callback when we were expecting it. if we aren't anticipating
937 * a socket close, then some error must have occurred. we'll
938 * just pass those errors up to the backend.
940 return plug_closing(p
->plug
, p
->closing_error_msg
,
941 p
->closing_error_code
,
942 p
->closing_calling_back
);
945 if (change
== PROXY_CHANGE_SENT
) {
946 /* some (or all) of what we wrote to the proxy was sent.
947 * we don't do anything new, however, until we receive the
948 * proxy's response. we might want to set a timer so we can
949 * timeout the proxy negotiation after a while...
954 if (change
== PROXY_CHANGE_ACCEPTING
) {
955 /* we should _never_ see this, as we are using our socket to
956 * connect to a proxy, not accepting inbound connections.
957 * what should we do? close the socket with an appropriate
960 return plug_accepting(p
->plug
, p
->accepting_sock
);
963 if (change
== PROXY_CHANGE_RECEIVE
) {
964 /* we have received data from the underlying socket, which
965 * we'll need to parse, process, and respond to appropriately.
971 * version number (1 byte) = 5
972 * authentication method (1 byte)
973 * authentication methods:
974 * 0x00 = no authentication
976 * 0x02 = username/password
978 * 0xff = no acceptable methods
982 if (bufchain_size(&p
->pending_input_data
) < 2)
983 return 1; /* not got anything yet */
985 /* get the response */
986 bufchain_fetch(&p
->pending_input_data
, data
, 2);
989 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned unexpected version",
990 PROXY_ERROR_GENERAL
, 0);
994 if (data
[1] == 0x00) p
->state
= 2; /* no authentication needed */
995 else if (data
[1] == 0x01) p
->state
= 4; /* GSSAPI authentication */
996 else if (data
[1] == 0x02) p
->state
= 5; /* username/password authentication */
997 else if (data
[1] == 0x03) p
->state
= 6; /* CHAP authentication */
999 plug_closing(p
->plug
, "Proxy error: SOCKS proxy did not accept our authentication",
1000 PROXY_ERROR_GENERAL
, 0);
1003 bufchain_consume(&p
->pending_input_data
, 2);
1006 if (p
->state
== 7) {
1008 /* password authentication reply format:
1009 * version number (1 bytes) = 1
1010 * reply code (1 byte)
1016 if (bufchain_size(&p
->pending_input_data
) < 2)
1017 return 1; /* not got anything yet */
1019 /* get the response */
1020 bufchain_fetch(&p
->pending_input_data
, data
, 2);
1023 plug_closing(p
->plug
, "Proxy error: SOCKS password "
1024 "subnegotiation contained wrong version number",
1025 PROXY_ERROR_GENERAL
, 0);
1031 plug_closing(p
->plug
, "Proxy error: SOCKS proxy refused"
1032 " password authentication",
1033 PROXY_ERROR_GENERAL
, 0);
1037 bufchain_consume(&p
->pending_input_data
, 2);
1038 p
->state
= 2; /* now proceed as authenticated */
1041 if (p
->state
== 8) {
1043 ret
= proxy_socks5_handlechap(p
);
1044 if (ret
) return ret
;
1047 if (p
->state
== 2) {
1050 * version number (1 byte) = 5
1051 * command code (1 byte)
1055 * reserved (1 byte) = 0x00
1056 * address type (1 byte)
1058 * 3 = domainname (first byte has length, no terminating null)
1060 * dest. address (variable)
1061 * dest. port (2 bytes) [network order]
1068 type
= sk_addrtype(p
->remote_addr
);
1069 if (type
== ADDRTYPE_IPV4
) {
1070 len
= 10; /* 4 hdr + 4 addr + 2 trailer */
1071 command
[3] = 1; /* IPv4 */
1072 sk_addrcopy(p
->remote_addr
, command
+4);
1073 } else if (type
== ADDRTYPE_IPV6
) {
1074 len
= 22; /* 4 hdr + 16 addr + 2 trailer */
1075 command
[3] = 4; /* IPv6 */
1076 sk_addrcopy(p
->remote_addr
, command
+4);
1078 assert(type
== ADDRTYPE_NAME
);
1080 sk_getaddr(p
->remote_addr
, command
+5, 256);
1081 command
[4] = strlen(command
+5);
1082 len
= 7 + command
[4]; /* 4 hdr, 1 len, N addr, 2 trailer */
1085 command
[0] = 5; /* version 5 */
1086 command
[1] = 1; /* CONNECT command */
1090 command
[len
-2] = (char) (p
->remote_port
>> 8) & 0xff;
1091 command
[len
-1] = (char) p
->remote_port
& 0xff;
1093 sk_write(p
->sub_socket
, command
, len
);
1099 if (p
->state
== 3) {
1102 * version number (1 bytes) = 5
1103 * reply code (1 byte)
1105 * 1 = general SOCKS server failure
1106 * 2 = connection not allowed by ruleset
1107 * 3 = network unreachable
1108 * 4 = host unreachable
1109 * 5 = connection refused
1111 * 7 = command not supported
1112 * 8 = address type not supported
1113 * reserved (1 byte) = x00
1114 * address type (1 byte)
1116 * 3 = domainname (first byte has length, no terminating null)
1118 * server bound address (variable)
1119 * server bound port (2 bytes) [network order]
1124 /* First 5 bytes of packet are enough to tell its length. */
1125 if (bufchain_size(&p
->pending_input_data
) < 5)
1126 return 1; /* not got anything yet */
1128 /* get the response */
1129 bufchain_fetch(&p
->pending_input_data
, data
, 5);
1132 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned wrong version number",
1133 PROXY_ERROR_GENERAL
, 0);
1140 strcpy(buf
, "Proxy error: ");
1143 case 1: strcat(buf
, "General SOCKS server failure"); break;
1144 case 2: strcat(buf
, "Connection not allowed by ruleset"); break;
1145 case 3: strcat(buf
, "Network unreachable"); break;
1146 case 4: strcat(buf
, "Host unreachable"); break;
1147 case 5: strcat(buf
, "Connection refused"); break;
1148 case 6: strcat(buf
, "TTL expired"); break;
1149 case 7: strcat(buf
, "Command not supported"); break;
1150 case 8: strcat(buf
, "Address type not supported"); break;
1151 default: sprintf(buf
+strlen(buf
),
1152 "Unrecognised SOCKS error code %d",
1156 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
1162 * Eat the rest of the reply packet.
1164 len
= 6; /* first 4 bytes, last 2 */
1166 case 1: len
+= 4; break; /* IPv4 address */
1167 case 4: len
+= 16; break;/* IPv6 address */
1168 case 3: len
+= (unsigned char)data
[4]; break; /* domain name */
1170 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned "
1171 "unrecognised address format",
1172 PROXY_ERROR_GENERAL
, 0);
1175 if (bufchain_size(&p
->pending_input_data
) < len
)
1176 return 1; /* not got whole reply yet */
1177 bufchain_consume(&p
->pending_input_data
, len
);
1184 if (p
->state
== 4) {
1185 /* TODO: Handle GSSAPI authentication */
1186 plug_closing(p
->plug
, "Proxy error: We don't support GSSAPI authentication",
1187 PROXY_ERROR_GENERAL
, 0);
1191 if (p
->state
== 5) {
1192 char *username
= conf_get_str(p
->conf
, CONF_proxy_username
);
1193 char *password
= conf_get_str(p
->conf
, CONF_proxy_password
);
1194 if (username
[0] || password
[0]) {
1195 char userpwbuf
[255 + 255 + 3];
1197 ulen
= strlen(username
);
1198 if (ulen
> 255) ulen
= 255; if (ulen
< 1) ulen
= 1;
1199 plen
= strlen(password
);
1200 if (plen
> 255) plen
= 255; if (plen
< 1) plen
= 1;
1201 userpwbuf
[0] = 1; /* version number of subnegotiation */
1202 userpwbuf
[1] = ulen
;
1203 memcpy(userpwbuf
+2, username
, ulen
);
1204 userpwbuf
[ulen
+2] = plen
;
1205 memcpy(userpwbuf
+ulen
+3, password
, plen
);
1206 sk_write(p
->sub_socket
, userpwbuf
, ulen
+ plen
+ 3);
1209 plug_closing(p
->plug
, "Proxy error: Server chose "
1210 "username/password authentication but we "
1212 PROXY_ERROR_GENERAL
, 0);
1216 if (p
->state
== 6) {
1218 ret
= proxy_socks5_selectchap(p
);
1219 if (ret
) return ret
;
1224 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1225 PROXY_ERROR_UNEXPECTED
, 0);
1229 /* ----------------------------------------------------------------------
1230 * `Telnet' proxy type.
1232 * (This is for ad-hoc proxies where you connect to the proxy's
1233 * telnet port and send a command such as `connect host port'. The
1234 * command is configurable, since this proxy type is typically not
1235 * standardised or at all well-defined.)
1238 char *format_telnet_command(SockAddr addr
, int port
, Conf
*conf
)
1240 char *fmt
= conf_get_str(conf
, CONF_proxy_telnet_command
);
1242 int retlen
= 0, retsize
= 0;
1244 #define ENSURE(n) do { \
1245 if (retsize < retlen + n) { \
1246 retsize = retlen + n + 512; \
1247 ret = sresize(ret, retsize, char); \
1251 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
1252 * %%, %host, %port, %user, and %pass
1255 while (fmt
[eo
] != 0) {
1257 /* scan forward until we hit end-of-line,
1258 * or an escape character (\ or %) */
1259 while (fmt
[eo
] != 0 && fmt
[eo
] != '%' && fmt
[eo
] != '\\')
1262 /* if we hit eol, break out of our escaping loop */
1263 if (fmt
[eo
] == 0) break;
1265 /* if there was any unescaped text before the escape
1266 * character, send that now */
1269 memcpy(ret
+ retlen
, fmt
+ so
, eo
- so
);
1275 /* if the escape character was the last character of
1276 * the line, we'll just stop and send it. */
1277 if (fmt
[eo
] == 0) break;
1279 if (fmt
[so
] == '\\') {
1281 /* we recognize \\, \%, \r, \n, \t, \x??.
1282 * anything else, we just send unescaped (including the \).
1289 ret
[retlen
++] = '\\';
1295 ret
[retlen
++] = '%';
1301 ret
[retlen
++] = '\r';
1307 ret
[retlen
++] = '\n';
1313 ret
[retlen
++] = '\t';
1320 /* escaped hexadecimal value (ie. \xff) */
1321 unsigned char v
= 0;
1326 if (fmt
[eo
] >= '0' && fmt
[eo
] <= '9')
1328 else if (fmt
[eo
] >= 'a' && fmt
[eo
] <= 'f')
1329 v
+= fmt
[eo
] - 'a' + 10;
1330 else if (fmt
[eo
] >= 'A' && fmt
[eo
] <= 'F')
1331 v
+= fmt
[eo
] - 'A' + 10;
1333 /* non hex character, so we abort and just
1334 * send the whole thing unescaped (including \x)
1337 ret
[retlen
++] = '\\';
1342 /* we only extract two hex characters */
1358 memcpy(ret
+retlen
, fmt
+ so
, 2);
1365 /* % escape. we recognize %%, %host, %port, %user, %pass.
1366 * %proxyhost, %proxyport. Anything else we just send
1367 * unescaped (including the %).
1370 if (fmt
[eo
] == '%') {
1372 ret
[retlen
++] = '%';
1375 else if (strnicmp(fmt
+ eo
, "host", 4) == 0) {
1378 sk_getaddr(addr
, dest
, lenof(dest
));
1379 destlen
= strlen(dest
);
1381 memcpy(ret
+retlen
, dest
, destlen
);
1385 else if (strnicmp(fmt
+ eo
, "port", 4) == 0) {
1386 char portstr
[8], portlen
;
1387 portlen
= sprintf(portstr
, "%i", port
);
1389 memcpy(ret
+ retlen
, portstr
, portlen
);
1393 else if (strnicmp(fmt
+ eo
, "user", 4) == 0) {
1394 char *username
= conf_get_str(conf
, CONF_proxy_username
);
1395 int userlen
= strlen(username
);
1397 memcpy(ret
+retlen
, username
, userlen
);
1401 else if (strnicmp(fmt
+ eo
, "pass", 4) == 0) {
1402 char *password
= conf_get_str(conf
, CONF_proxy_password
);
1403 int passlen
= strlen(password
);
1405 memcpy(ret
+retlen
, password
, passlen
);
1409 else if (strnicmp(fmt
+ eo
, "proxyhost", 9) == 0) {
1410 char *host
= conf_get_str(conf
, CONF_proxy_host
);
1411 int phlen
= strlen(host
);
1413 memcpy(ret
+retlen
, host
, phlen
);
1417 else if (strnicmp(fmt
+ eo
, "proxyport", 9) == 0) {
1418 int port
= conf_get_int(conf
, CONF_proxy_port
);
1421 sprintf(pport
, "%d", port
);
1422 pplen
= strlen(pport
);
1424 memcpy(ret
+retlen
, pport
, pplen
);
1429 /* we don't escape this, so send the % now, and
1430 * don't advance eo, so that we'll consider the
1431 * text immediately following the % as unescaped.
1434 ret
[retlen
++] = '%';
1438 /* resume scanning for additional escapes after this one. */
1442 /* if there is any unescaped text at the end of the line, send it */
1445 memcpy(ret
+ retlen
, fmt
+ so
, eo
- so
);
1456 int proxy_telnet_negotiate (Proxy_Socket p
, int change
)
1458 if (p
->state
== PROXY_CHANGE_NEW
) {
1459 char *formatted_cmd
;
1461 formatted_cmd
= format_telnet_command(p
->remote_addr
, p
->remote_port
,
1464 sk_write(p
->sub_socket
, formatted_cmd
, strlen(formatted_cmd
));
1465 sfree(formatted_cmd
);
1471 if (change
== PROXY_CHANGE_CLOSING
) {
1472 /* if our proxy negotiation process involves closing and opening
1473 * new sockets, then we would want to intercept this closing
1474 * callback when we were expecting it. if we aren't anticipating
1475 * a socket close, then some error must have occurred. we'll
1476 * just pass those errors up to the backend.
1478 return plug_closing(p
->plug
, p
->closing_error_msg
,
1479 p
->closing_error_code
,
1480 p
->closing_calling_back
);
1483 if (change
== PROXY_CHANGE_SENT
) {
1484 /* some (or all) of what we wrote to the proxy was sent.
1485 * we don't do anything new, however, until we receive the
1486 * proxy's response. we might want to set a timer so we can
1487 * timeout the proxy negotiation after a while...
1492 if (change
== PROXY_CHANGE_ACCEPTING
) {
1493 /* we should _never_ see this, as we are using our socket to
1494 * connect to a proxy, not accepting inbound connections.
1495 * what should we do? close the socket with an appropriate
1498 return plug_accepting(p
->plug
, p
->accepting_sock
);
1501 if (change
== PROXY_CHANGE_RECEIVE
) {
1502 /* we have received data from the underlying socket, which
1503 * we'll need to parse, process, and respond to appropriately.
1508 /* proxy activate will have dealt with
1509 * whatever is left of the buffer */
1513 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1514 PROXY_ERROR_UNEXPECTED
, 0);